In mobile stations, e.g. in mobile phones, for user identification, a smart card provided with a processor, a so-called SIM card (SIM=Subscriber Identity Module) is used, to which it is possible to store e.g. user-specific information. In the terminal device there is a card compartment for the smart card, from which the smart card can be removed when necessary. In the card compartment there are separate connectors against which the connector interfaces on the card settle for transferring information between the processor and the other components of the terminal device.
When the smart card has been inserted into the terminal device, it is usually locked by some means so that it could not move in its compartment. If the locking is not sufficient, the card can move in its compartment, in which case the connector interfaces on it do not necessarily touch the connectors in the compartment any more. Thereby, there may occur problems in the transfer of information between the processor and the device.
For example in mobile phones, a chargeable battery in other words accumulator is used as the current supply, for which there is a place of its own in the device structure from which the accumulator can be removed when necessary. When the accumulator has been mounted and attached in place to the device, the attachment and locking of the accumulator has to be such that it is allowed to move as little as possible in the place reserved for it. In practice, the locking methods of accumulator have, however, not always been sufficient, but the accumulator may have moved in its place, in which case the current supply of the device may have been disturbed.
A mobile phone may also comprise a separate cover for closing the accumulator place. Additional tasks of the accumulator cover may include pressing the accumulator against the device structure in order that the poles of the accumulator would keep all the time in touch with the connector interfaces corresponding to them. It is, however, possible that there is a little clearance left in between the cover and the device structure, in which case the cover does not press the accumulator with a sufficient force. If the accumulator, due to a clearance, moves too much, also the accumulator may move, which causes disturbances in the current supply of the device.
The goal of the invention is to avoid the above-mentioned problems and to achieve a solution which enables one to get the attachment and locking of a smart card, accumulator and possible accumulator cover to the terminal device more dependable than before and thus also the operating reliability of the device better than before.